Why is my dry rub almost tasteless when the meat comes off the smoker?

I have a very good dry rub that imparts an excellent flavor to pork, chicken and fish. It is pungent to the nose when in the bottle and is always made fresh. It is applied liberally, covering the surface of the meat being smoked. The situation is this: I apply the rub approx. an hour prior to cooking. This allows me time to get my charcoal heated and prepare my smoker. The smoker is kept at a constant 200-225 degrees and I use various types of wood (oak, hickory, maple, pecan) depending on the type of meat and flavor desired. When the meat is ready to come off the smoker I always try a small portion at that time and I find that the rub is almost flavorless, however if I allow the meat to cool down considerably the flavor begins to assert itself. My usual method is to cook the day before, put the smoked meats in the fridge in either a plastic storage bag or wrapped in foil, place the meats in foil pans, covered, and reheat the next day for 1.5 to 2 hours at 200 degrees, either in the oven or on the smoker. The flavor is magnificent and the aroma is to die for! I am just curious as to why the rub flavors are absent right out of the smoker. Thanks for your input.